Manufacture of lead electrode for accumulators



Patented Sept; 6 1927.

- UNITED STATES ALBERT STRASSER, OF RORSCHACH, SWITZEBLANDF MANUFACTURE OF LEI-LID ELECTRODE FOR ACCUMULATORS.

No Drawing. Application filed August 15, 1925, Serial No. 50,488, and in $Witzer1and August 23, 1924.

' the alloy and to thus give to the active mass :1 uniformporosity throughout with recrystallization of lead. Y

The present invention relates to an improvement in-the process above referred to,

which consists in treating the electrode body,

before its extracting treatment with water,

in a weak caustic soda lye, for example of 6 per cent, and in subjecting the same, after the operation of extraction by water, within an electrolyte to the action of a convenient electric current, having for example a current density of 0.2 ampere per centimetre in square to eliminate any residual alkali metal from the lead mass. 7 I Y The treatment of the electrodebody in caustic soda lye, which maybe of a duratio'nlof about one hour, isintended to avoid a too intense dcvelopement of hydrogen and consequently a too great ncrease .of volume. The "electric treatment" there- I of the mass.

of within an electrolyte, "which may be con stituted for example by a 2 to 3 per cent solution of perchlorate of sodium or perchlorate of potassium, has the object to perform the electrolytic dissolution of the alkali metal crystalswhich remained undissolved' on the preceding watery extracting operation and to eliminate in this was any residual alkali metal from the leadfbody which then constitutes a uniform spongious mass. 40

The thus treated accumulator electrodes are then thoroughly washed out in distilled water and thereupon subjected to an anodic and cathodic polarization in 'a 3 to at per cent sulphuric acid solution. I The electrodes obtained according to the present improvement constitute a thoroughly spongious and pure leadbody and owing to the absence of any alkali metal do not, show any tendency of self-discharge.

What I claim is:

A- process forthe manufacture of lead electrodes forflaccumulators, consisting in alloying metallic lead with an alkali metal capable of reducing water, then introducing 65 this alloy into a. hollow perforated insulating body, thereupon treating the whole in a caustic soda lye and dipping it afterwards fora suthcient' time into water for extracting the alkali' m'etalfrom the alloy, and 60 finally subjecting the electrode body within an electrolyteto the action of a convenient 1 electric current. 1

In Witness whereof I have: hereunto signed my name this 4th day of August, 1925.

' g m ALBERT STRASSER. 

